mpc83xx pci: Round up memory size in inbound window.

The current calculation will fail to cover all memory if
its size is not a power of two.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
diff --git a/cpu/mpc83xx/pci.c b/cpu/mpc83xx/pci.c
index 5b8eeb7..ab0760b 100644
--- a/cpu/mpc83xx/pci.c
+++ b/cpu/mpc83xx/pci.c
@@ -83,7 +83,7 @@
 	pci_ctrl->pibar1 = 0;
 	pci_ctrl->piebar1 = 0;
 	pci_ctrl->piwar1 = PIWAR_EN | PIWAR_PF | PIWAR_RTT_SNOOP |
-	                   PIWAR_WTT_SNOOP | (__ilog2(gd->ram_size) - 1);
+	                   PIWAR_WTT_SNOOP | (__ilog2(gd->ram_size - 1));
 
 	i = hose->region_count++;
 	hose->regions[i].bus_start = 0;